1. Field of the Invention
The present invention concerns multimedia presentations, and particularly the superimposition of visual cues over elements in the multimedia presentation, with both temporal and spatial synchronization of the visual cues to the presentation itself.
2. Description Of The Related Art
Various mark-up languages have been proposed for use in Internet and Intranet browsing of web-based pages. Currently, the most popular mark-up language is hypertext mark-up language (HTML). HTML defines spatial relationships and visual appearance of a web page when the page is displayed at a user's browser.
One disadvantage of HTML is that it is difficult to display a multimedia presentation using HTML alone. Moreover, it is nearly impossible to synchronize different multimedia presentations within the same web page. Thus, although with HTML it is possible, though difficult, to display a video file, it is nearly impossible to synchronize two different video files for simultaneous display on the same web page.
In response to these shortcomings, the World Wide Web Consortium Working Group on synchronized multimedia has proposed an extensible mark-up language (XML) based language that permits synchronization of multimedia presentations. A proposed standard has been circulated, entitled “Synchronized Multimedia Integration Language” (SMIL), version 1.0, the contents of which are incorporated herein by reference. Importantly, the SMIL standard permits both sequential and parallel presentation of multimedia files, thereby permitting synchronization either serially or parallelly of multimedia presentations.
Despite the advantages of the SMIL standard, there are situations in which it is desired to superimpose visual cues onto multimedia elements. For example, in a situation where the synchronized multimedia presentation is a real estate marketing promotion comprising a series of still images with a voice-over tour explaining highlights of the still images, it might be desirable to superimpose a visual cue (such as an arrow) on the video stills with the position of the cue synchronized with the voice explanations.
With SMIL, however, it is not now possible to provide for superimposition of a visual cue over a multimedia presentation, with the visual cue synchronized both temporally and spatially with the multimedia presentation.